Electro-magnetic system constructed as an independent prefabricated unit capable of mounting without adjustment



3,451,022 ENDENT June 17, 1969 H. KRAUTWALD ET AL ELECTRO MAGNETIC SYSTEM CONSTRUCTED AS AN INDEP PREFABRICATED UNIT CAPABLE OF MOUNTING Sheet WITHOUT ADJUSTMENT Filed May 29, 1967 IN V H" ENTORS aa/wa/a Werner B0 ATTYS.

June 1959 H. KRAUTWALD ET AL 3,451,022

ELECTRO-MAGNETIC SYSTEM CONSTRUCTED AS AN INDEPENDENT PREFABRICATED UNIT CAPABLE OF MOUNTING WITHOUT ADJUSTMENT Filed May 29, 1967 IN VENTORS fierer/ A4 aq/Wd/d 7%2/729 ga s h cfi 6190/ 9 flq'yner ,6 ATTYS.

United States Patent U.S. Cl. 335-281 8 Claims ABSTRACT OF THE DISCLOSURE A three-legged E-shaped magnetic system. The outer legs of the E form a U-shaped yoke which is constructed from a single piece of fiat material. An energizing coil is located on the central, cylindrically shaped leg. An armature located adjacent the free ends of the legs is retained in operative position by a leaf spring secured to the outer yoke legs. A slide member connected to the armature actuates an associated contact arrangement.

The invention relates to an electro-magnetic system, particularly for multiple contact relays of the miniaturized type, which can be mechanically manufactured as an independent prefabricated unit and can be mounted without adjustment, utilizing a three-legged E-shaped magnetic system with an energizing winding arranged on the center leg. The construction of such an electromagnetic system must be such that a high efliciency is achieved. The reason for this requirement lies, firstof all, in the fact that in a small relay with a large number of contacts, exceeding the permissible values with respect to operating efiiciency or heating of the electro-magnetic system can be avoided only if the overall efficiency is high. Moreover, to enable a mechanized fabrication, which is almost always required in mass production, the electro-magnetic system must be so constructed that no machining operations and only a simple mounting operation are necessary.

In accordance with the invention, in an electro-magnetic system of the type initially described, these requirements are fulfilled by an arrangement in which the yoke of a U-shaped structure, constructed from a single piece of flat material and provided with latch members on both outer surfaces, have disposed therebetween a centrally positioned cylindrically-shaped center leg, with a leaf spring secured, preferable by welding, on the yoke legs serving to retain an armature arranged adjacent the free ends of the yoke legs, whereby, by means of projections on the armature, a slide member can be arranged actuating the assigned contact arrangement, with the slide being retained in operative position by a claw-like portion of the leaf spring.

The advantages arising from the features of the invention are the simplicity of fabrication and the high efficiency of the electro-magnetic system. As a result of the constructional design the magnetic flux leaving the cylindrical center leg, forming the core of the energizing coil, is divided in the armature so that its thickness and therewith its mass can be kept relatively small. As a result, under normal operating conditions additional starting torques are created in the flux return air gaps between the armature and the free ends of the yoke legs. The absence of such flux return air gaps results, as a rule, in low efficiency in such a system. a

The U-shaped yoke consisting of a single piece of flat material formed with yoke legs presents the possibility of enlarging the electro-rnagnetic system in conformity with 3,451,022 Patented June 17, 1969 specific contact requirement, by merely accordingly lengthening only the yoke legs and the center leg, along with the energizing coil without any change in the fundamental constructional design. A further favorable feature of the invention in the mechanical fabrication of the electromagnetic system resides in the fact that the leaf spring that serves to hold the armature is provided with a correspondingly punched-out end portion for retaining the slide member in its operative position. Furthermore, the fact that the yoke legs of the electromagnetic system are provided with latch members on both outer surfaces permits the securement of the electro-magnetic system in a support provided with corresponding apertures for the receipt of the latch members in a fixed and a non-fixed manner along with the corresponding arrangement, as a compact prefabricated structure.

As such apertures in the support can be constructed with corresponding small tolerances, an accurate mounting of the electro-magnetic system without the necessity of an otherwise time consuming adjustment can be achieved.

In the further development of the invention, the leaf spring used for retaining the armature is connected with the armature by means of rivets, whereby the projections resulting from the riveting form means which facilitates the centering of the armature in assembly. For reasons of expediency the armature may be provided with arms at the height of the claw-like end of the leaf spring which are symmetrically offset and lock in the slide from its operating side. In further desirable developments of the invention the round center leg which acts as an iron core for the energizing coil may be secured to the connecting part of the U-shaped yoke by a press fit. The spool of the energizing coil which can be constructed as an injection-molded part can, for the sake of expediency, be retained on the center leg which acts as an iron core by frictional connection. The main power supply lines of the energizing coil which preferably can be arranged in the terminal field of the relay can be constructed for use as a soldered or plug type connection.

Further details of the invention will be apparent from the following description of an illustrative embodiment. In the drawings, wherein like reference characters indicate like or corresponding parts:

FIG. 1 is a perspective view of an electno-magnetic system according to the invention, with portions broken away to show the details thereof; and

FIGS. 2a, 2b and 2c likewise are perspective views respectively illustrating the individual parts of such a relay on a reduced scale to that of FIG. 1.

The electro-magnetic system for a mechanized and adjustment-free manufacturable multiple contact relay consists, in accordance with the invention, mainly of a U-shaped yoke B, having legs 1a and 1b, in which on the connecting portion between such legs there is disposed an iron core 1c for the energizing coil 2, which is provided with a pole plate 10'. Extending outwardly from the two outer surfaces of the yoke legs 1a and 1b are latch members in the form of pins 1d for mounting the electro-magnetic system in a U-shaped support A, with the pins being disposed for positive and non-positive locking engagement therewith.

At one side of the yoke legs 1a and 1b is secured a leaf spring 5, preferably by welding, which serves to retain the armature 4 disposed adjacent the free ends of the yoke legs 1a and 1b, the armature 4 being connected to the leaf spring '5 by three rivets 6. To retain the armature in operative position with respect to jolting forces, it is provided with struck-out portions 4b which lock in corresponding recesses in the yoke legs 1a and 1b. Moreover,

the leaf spring 5 has a punched out arm which terminates in a claw-like upwardly directed portion a and serves to retain the slide C, illustrated in FIG. 2b, in operative position. The armature 4 has, approximately at the height of the clawlike end 5a of the leaf spring, symmetrically arranged projections or arms 4a which, in the mounting of the slide C, lock from below in the square apertures d1 of the slide. As to the operational dependability of the electro-magnctic system, the only accuracy requirement is that the armature 4 and the end surfaces of the yoke legs 1a and 1b are even. If it is necessary to enlarge the electro-magnetic system for the eflicient adaptation therof to agreater number of contacts, it is then only necessary to lengthen the yoke legs 1a and 1b, as well as the round center leg and the energizing coil 2. The relay capacity is thus primarily enlarged merely by the additional capacity of the magnetic system.

The U-shaped support A of FIG. 2a can readily receive the electro-magnetic system designated B in FIG. 20. The apertures d2 and d2 in the support A provided for the reception of the pins 1d can be made with a small tolerance. In order to actuate the contact units, of which for the sake of simplicity only the contact unit D is represented, the actuating slide C (FIG. 2b) is provided, which is supported on the offset arms 4a of the armature, which extend through the apertures d1 and maintained in operative position by the claw-shaped end 5a of the leaf spring 5 (FIG. 1). It is apparent from the above description that a relay of this type not only can be produced mechanically and simply, but also that a practical assembly is possible without adjustment. It will also be noted that the construction of a relay with the described electro-magnetic system meets varying requirements with respect to the capacity of the electro-magnetic system and therewith the various requirements with regard to the number of contacts without the necessity of changing the constructional designs.

Obviously, the invention is not limited to the illustrative embodiment. It should especially be pointed out that for alternate current operation the center leg can, as known in the prior art, have a short circuiting shading ring on its end which is turned toward the armature. Furthermore, to enable operation in dependence upon the direction of the current, at least one permanent magnet can be included, without changing the fundamental construction, in the fiow circuit of the magnetic system, whereby in such case, if necessary, corresponding pole plates can be provided for guiding the necessary permanent flow.

Changes may be made within the scope and spirit of the appended claims which define what is believed to be new and desired to have protected by Letters Patent.

We claim:

1. An electro-magnetic system for mechanized manufacture as an independent prefabricated unit, which can be mounted without adjustment, particularly for a multiple contact relay of the miniatiurized type, comprising a three-legged E-shaped magnetic system, the outer legs of which comprise the legs of a U-shaped yoke constructed from a single piece of flat material, and the center leg of which is of cylindrical shape and disposed between said outer yoke legs, an energizing coil disposed on Said center leg, an armature disposed adjacent the free ends of said legs, a leaf spring secured to the outer yoke legs forming means for retaining said armature in operative position, a slide member for actuating a contact arrangement associated therewith, means carried by said armature for transmitting move-ment of said armature to said slide member to actuate the latter, and means formed from said leaf spring, cooperable with said movement transmitting means carried by said armature for retaining said slide member in operative position with respect to said armature.

2. An electro-maguetic system according to claim 1, wherein the armature is provided with projections struck therefrom disposed in corresponding recesses in the yoke legs for preventing shifting of the armature with respect thereto if subjected to jolting or jarring.

3. An electro-magnetic system according to claim 1, wherein said leaf spring is connected with the armature by means of rivets.

4. An electro-magnetic system according to claim 3, wherein the projections resulting from the riveting serves as centering means for said armature.

5. An electro-magnetic system according to claim 1, wherein said movement transmitting means on said armature is constructed to interlock with means on said slide member, and said retaining means is constructed with a claw-shaped portion engageable with said slide member to prevent disconnection of the latter from said interlocking means on said armature.

6. An electro-magnetic system according to claim '5, wherein said movement transmitting means on said armature comprises projecting arms on said armature disposed at the height of the claw-shaped portion of the leaf spring, said arms being symmetrically offset with respect to the armature and inserted in openings in the slide member, from the operating side thereof, which openings define the interlocking means on said slide member.

7. An electro-magnetic system according to claim 1, wherein the cylindrical center leg which forms an iron core for the energizing coil is secured to the connecting member of the U-shaped yoke by a press fit.

8. An electro-mangetic system according to claim 1, wherein the spool of the energizing coil, preferably constructed as an injection-molded part, is frictionally engaged with the center leg by a force-fit.

References Cited UNITED STATES PATENTS 2,472,709 6/1949 Knapp 335126 2,638,514 5/1953 Martin 335-230 XR 2,917,600 12/1959 Smith 335-281 XR 3,195,023 7/1965 Ueberschuss et al. 335-230 BERNARD A. GILHEANY, Primary Examiner.

D. M. MORGAN, AssistantExaminer.

US. Cl. X.R. 335-126, 

